Difference between revisions of "Cristobalite"
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== Description == | == Description == | ||
| − | A translucent [ | + | A translucent [[quartz]] mineral named after Cerro San Cristobal, Mexico where it was first identified in 1887. Cristobalite is a natural, refractory material formed in volcanic rock. It can be made synthetically when quartz is heated above 1050 C. Small amounts of cristobalite in a ceramic glaze formula minimize crazing. [[Opal|Opals]] contain masses of microscopic cristobalite crystals. |
== Synonyms and Related Terms == | == Synonyms and Related Terms == | ||
Revision as of 13:49, 13 January 2014
Description
A translucent Quartz mineral named after Cerro San Cristobal, Mexico where it was first identified in 1887. Cristobalite is a natural, refractory material formed in volcanic rock. It can be made synthetically when quartz is heated above 1050 C. Small amounts of cristobalite in a ceramic glaze formula minimize crazing. Opals contain masses of microscopic cristobalite crystals.
Synonyms and Related Terms
cristobalita (Esp.); cristobalite (Fr., Port.)
Other Properties
Luster=Glassy Streak = white Nonfluorescent
| Composition | SiO2 |
|---|---|
| CAS | 14464-46-1 |
| Mohs Hardness | 6.5 |
| Density | 2.2 |
| Refractive Index | 1.485-1.487 |
Additional Information
WebMinerals: Cristobalite
Comparisons
Properties of Common Gemstones
Authority
- G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 647
- Robert Fournier, Illustrated Dictionary of Practical Pottery, Chilton Book Company, Radnor, PA, 1992
- Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997